Hydroponics or Soilless Culture

Historically, hydroponics is not a new field; plant physiologists have known and used it for some 100 years. Inevitably, some enthusiasts got carried away.Claims were made of enormous potential yields; skyscraper tops were said to be capable of producing enough food for all of their occupants; and closets, basements, garages, etc. were wishfully converted into fields for hydroponic culture. Numerous publications on the subject appeared during this period. Basic requirements for hydropinc techniques are given along with examples of where soilless culture has been used commercially

Mapping London's Innovation Networks

A wide range of authors have highlighted the potential benefits for entrepreneurial companies that engage in effective networking along and across the supply-chain. As many organisations have downsized or outsourcedbasic research activities Universities have an increasingly important role within such networks. A number of UK initiatives have been established to encourage greater 'entanglement' between academia and commerce; the London Technology Network is one example which is intended to encourage interactions between London's leading research institutes and innovative businesses.Using the detailed data acquired by this network this paper is intended to presents an exploratory analysis of such activities with the aim of establishing the extent to which company size, sector and/or location play a significant role in participation in the network's activities. A wide range of authors have highlighted the potential benefits for entrepreneurial companies that engage in effective networking along and across the supply-chain. As many organisations have downsized or outsourced basic research activities Universities have an increasingly important role within such networks. A number of UK initiatives have been established to encourage greater 'entanglement' between academia and commerce; the London Technology Network is one example which is intended to encourage interactions between London's leading research institutes and innovative businesses.Using the detailed data acquired by this network this paper is intended to presents an exploratory analysis of such activities with the aim of establishing the extent to which company size, sector and/or location play a significant role in participation in the network's activities

The 1979 eclipse of zeta Aurigae

Observations of the system zeta Aurigae made around primary eclipse are described, and their significance is discussed in a preliminary fashion

Switching circuit Patent

Solid state circuit for switching alternating current input signal as function of direct current gating transisto

Resummed thermodynamic perturbation theory for bond cooperativity in associating fluids with small bond angles: Effects of steric hindrance and ring formation

In this paper we develop a thermodynamic perturbation theory for two site associating fluids which exhibit bond cooperativity. We include both steric hindrance and ring formation such that the equation of state is bond angle dependent. Here the bond angle is the angle separating the centers of the two association sites. As a test, new Monte Carlo simulations are performed, and the theory is found to accurately predict the internal energy as well as the distribution of associated clusters as a function of bond angle and bond cooperativity.Comment: To appear in The Journal of Chemical Physic

Quasichemical theory and the description of associating fluids relative to a reference: Multiple bonding of a single site solute

We derive an expression for the chemical potential of an associating solute in a solvent relative to the value in a reference fluid using the quasichemical organization of the potential distribution theorem. The fraction of times the solute is not associated with the solvent, the monomer fraction, is expressed in terms of (a) the statistics of occupancy of the solvent around the solute in the reference fluid and (b) the Widom factors that arise because of turning on solute-solvent association. Assuming pair-additivity, we expand the Widom factor into a product of Mayer f-functions and the resulting expression is rearranged to reveal a form of the monomer fraction that is analogous to that used within the statistical associating fluid theory (SAFT). The present formulation avoids all graph-theoretic arguments and provides a fresh, more intuitive, perspective on Wertheim's theory and SAFT. Importantly, multi-body effects are transparently incorporated into the very foundations of the theory. We illustrate the generality of the present approach by considering examples of multiple solvent association to a colloid solute with bonding domains that range from a small patch on the sphere, a Janus particle, and a solute whose entire surface is available for association

Development and Verification of a Flight Stack for a High-Altitude Glider in Ada/SPARK 2014

SPARK 2014 is a modern programming language and a new state-of-the-art tool set for development and verification of high-integrity software. In this paper, we explore the capabilities and limitations of its latest version in the context of building a flight stack for a high-altitude unmanned glider. Towards that, we deliberately applied static analysis early and continuously during implementation, to give verification the possibility to steer the software design. In this process we have identified several limitations and pitfalls of software design and verification in SPARK, for which we give workarounds and protective actions to avoid them. Finally, we give design recommendations that have proven effective for verification, and summarize our experiences with this new language

Single-stage experimental evaluation of boundary layer blowing techniques for high lift stator blades. 1 - Compressor design

Boundary layer blowing techniques for high lift stator blades in axial flow compressor